Electric heating elements

Abstract

An electric resistance heating element, comprising at least two elongated dielectric bodies, each having a plurality of openings extending longitudinally thereon in radially displaced, parallel relation. Three metal pins fit into openings in the dielectric bodies and at least certain maintain the latter in longitudinally aligned relation. A resistance wire is wound on each of the bodies, each wire having longitudinally spaced terminals. One of the terminals of each resistance wire is electrically connected to one pin; the opposite terminal of one resistance wire is electrically connected to a second pin; and the opposite terminal of the other resistance wire is electrically connected to the third pin, whereby the one pin serves as a common electrical connection for both resistance wires, and the second and third pins serve as separate electrical connections to the respective resistance wires, whereby separate electrical circuits may be established within the heating element. Our invention also makes it possible to provide three phase electrical connections between resistance wires separately wound on at least three dielectric cores. This is accomplished by properly orienting the cores so that the opposite terminals on each are aligned for electrical engagement with three terminal pins which pass through longitudinally aligned openings in the cores.

We claim: 
     
       1. An electric resistance heating element, comprising: a pair of elongated dielectric bodies, each having at least three openings extending longitudinally therethrough in simularly radially spaced, parallel relation,   three metallic terminal pins fitting into the openings in said dielectric bodies and at least certain pins maintaining said bodies in longitudinally aligned relation,   a resistance conductor on the surface of each of said bodies, each conductor having longitudinally spaced terminals, one of the terminals of each resistance conductor being electrically connected to one pin, the opposite terminal of one resistance conductor being electrically connected to a second pin, and the opposite terminal of the other resistance conductor being electrically connected to the third pin,   whereby said one pin serves as a common electrical connection for the resistance conductors on both dielectric bodies, and the second and the third pins serve as separate electrical connections to respective conductors.   
     
     
       2. The construction according to claim 1 wherein said resistance conductors are spirally wound about respective dielectric bodies, each having one terminal fitting into the aligned openings in which said one pin fits and in frictional engagement therewith to thereby establish electrical continuity therebetween, the other terminals of said resistance conductors fitting into respective ones of the aligned openings in which said second and third pins fit and in frictional engagement therewith to thereby establish electrical continuity therebetween. 
     
     
       3. The construction according to claim 1 wherein one resistance conductor possesses electrical characteristics for energization by a certain voltage impressed across said first and second pins, and said other resistance conductor possesses electrical characteristics for energization by a different voltage impressed across said first and third pins. 
     
     
       4. The construction according to claim 1 wherein all said pins extend outwardly from one end of said longitudinally aligned dielectric bodies, for connection to a source of electrical energy. 
     
     
       5. The construction according to claim 1 including an additional third dielectric body having a resistance conductor on its surface with spaced terminals, all three bodies having four openings extending longitudinally therethrough in similarly radially spaced, parallel relation, and wherein said one pin is also electrically connected to one terminal of said third body, and a fourth terminal pin within the fourth opening in said bodies and electrically connected to the opposite terminal of the coil on said third body.   
     
     
       6. The construction according to claim 1 wherein multiples of the two dielectric bodies are provided, the resistance conductor on each of the multiple of said bodies having opposite terminals connected to said three terminal pins in accordance with the two single bodies of claim 1. 
     
     
       7. The construction according to claim 5, wherein multiples of the three dielectric bodies are provided, the resistance conductor on each of the multiple of said bodies having opposite terminals connected to said four terminal pins in accordance with the three single bodies of claim 5. 
     
     
       8. An electric resistance heating element, comprising: a plurality of dielectric cores each having a plurality of openings extending longitudinally therethrough, said cores being adapted for longitudinal alignment with at least certain of their openings longitudinally aligned,   a plurality of terminal pins in number not exceeding the number of openings in each of said cores, at least certain of said pins fitting within the aligned openings to hold said cores in longitudinal alignment,   and a resistance wire coil wound on each core, one end of each coil being disposed within a common one of the aligned openings for electrical engagement with the terminal pin fitting therein, and the other end of respective coils being disposed each in a different one of the openings for electrical engagement with respective terminal pins within said different opening.   
     
     
       9. An electric resistance heating element, comprising: a plurality of dielectric cores, each having a plurality of openings extending longitudinally therethrough, said cores being adapted for longitudinal alignment with their openings longitudinally aligned,   a resistance coil wound on each core, having one end inserted within one core opening at one end of the core and an opposite end inserted within another core opening at the opposite end of the core,   a plurality of terminal pins in number not exceeding the number of openings in each of said cores, said pins fitting within the longitudinally aligned openings of the longitudinally aligned cores and the openings therein being radially oriented so that one terminal pin is in electrical engagement with each of said one coil end, and so that a different terminal pin is in electrical engagement with a respective one of said opposite coil ends.   
     
     
       10. An electric resistance heating element, comprising: three dielectric cores, each having a plurality of longitudinal openings, said cores being adapted for longitudinal alignment with their openings axially aligned,   a resistance coil wound on each core, having one end inserted within one core opening at one end of its core and an opposite end inserted with another core opening at the opposite end,   and a plurality of terminal pins, inserted within selected core openings, said cores being longitudinally aligned with their openings being radially oriented to provide predetermined engagement between coil ends and terminal pins for a three phase connection.   
     
     
       11. The construction according to claim 10 wherein one terminal pin electrically engages one end of each of two coils, another terminal pin, electrically engages the opposite end of one of said two coils and one end of the third coil, and a third terminal pin electrically engages the opposite end of the other of said two coils and the opposite end of said third coil, to form a three-phase Delta connection. 
     
     
       12. The construction according to claim 10 wherein each of said cores has four longitudinal openings for the reception of four terminal pins, one terminal pin being in electrical engagement with one end of each of the three resistance coils, and second, third and fourth terminal pins in electrical engagement with only the respective ones of the other ends of said coils, to provide a three-phase Y connection,   said one terminal pin providing a common electrical connection between all three coils and said second, third and fourth terminal pins being connectable to a three-phase power system.